import java.sql.*;

public class Main {
    public static void main(String[] args) {
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        //1.加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            //创建连接
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            connection = DriverManager.getConnection(url, "root", "Yan411328");
            if (connection != null) {
                System.out.println("连接成功");
            }
            //2.写sql
            String sql = "select * from user";

            //预编译sql
            preparedStatement = connection.prepareStatement(sql);

            //3.执行sql
            resultSet = preparedStatement.executeQuery();

            //4.遍历结果
            while (resultSet.next()) {
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id + " " + name + " " + pass);
            }

        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        } finally {

                try {
                    if (resultSet != null) {
                    resultSet.close();
                    }

                    if (preparedStatement != null) {
                        preparedStatement.close();
                    }
                    if (connection != null) {
                        connection.close();
                    }


                } catch (SQLException e) {
                    throw new RuntimeException(e);
                }



            //关闭资源


        }


    }
}